Cathode ray tube electrical connective means

ABSTRACT

Improved electrical connective means are provided for use in a cathode ray tube to effect a bridging connection between a funnel-oriented electrical transversal and a discrete area of the adjacent panel portion. The connective means comprises a metallic conductive button extending through the wall of the funnel and having a protuberance extending from the inner surface thereof. Mating with this protuberance, and affixed thereto, is a longitudinal resilient connective member extending to make pressured contact with a discrete area on the related panel portion of the envelope.

United States Patent [1 1 Davis et al.

[ Apr. 8, 1975 CATIIODE RAY TUBE ELECTRICAL CONNECTIVE MEANS [75]Inventors: Charles A. Davis, Auburn; Donald L. Say, Waterloo, both ofNY.

[73] Assignee: GTE Sylvania Incorporated,

Stamford, Conn.

[22] Filed: June 27, 1974 [21] App]. No.: 483,555

[52] 0.8. CI 313/482; 313/364 X [51] Int. Cl I-I0lj 29/02; HOlj 31/20[58] Field of Search 317/318, 325, 402, 407,

[56] References Cited UNITED STATES PATENTS 2,755,405 7/1956 Wilhelm313/404 2,951,179 8/1960 Evans 313/402 X 6/1969 Engels et a1. 313/482 x2/1970 Duistermaat et al. 313/404 Primary ExaminerRobert Sega] Attorney,Agent, or Firm-Norman ,l. OMalley; Frederick H. Rinn; Robert T. Orner[57] ABSTRACT Improved electrical connective means are provided for usein a cathode ray tube to effect a bridging connection between afunnel-oriented electrical transversal and a discrete area of theadjacent panel portion. The connective means comprises a metallicconductive button extending through the wall of the funnel and having aprotuberance extending from the inner surface thereof. Mating with thisprotuberance, and affixed thereto, is a longitudinal resilientconnective member extending to make pressured contact with a discretearea on the related panel portion of the envelope.

6 Claims, 4 Drawing Figures CATHODE RAY TUBE ELECTRICAL CONNECTIVE MEANSCROSS-REFERENCE TO RELATED APPLICATIONS This application contains matterdisclosed but not claimed in two related applications filed concurrentlyherewith and assigned to the assignee of the present invention. Theserelated applications are: Ser. No. 483,559 Attorneys Docket 8011,Shielding Means For A Cathode Ray Tube", and Ser. No. 483,554 AttorneysDocket 8062, Electrical Conductive Means For Traversing a CRT EnvelopeTo Effect Multiple Connections Therein.

BACKGROUND OF THE INVENTION This invention relates to electricalconnective means for a cathode ray tube and more particularly toelectrical connective means for effecting the conduction of a potentialfrom the funnel to panel portions of a cathode ray tube. In certaintypes of cathode ray tube construction, it is desired to effect anelectrical connection between a discrete funnel-related area and anassociated area disposed on the adjacent panel portion. For example, incolor cathode ray tubes of post-deflection structure, it has been ausual practice to supply the screen potential by utilizing a separatehigh voltage connection through the tube envelope in conjunction with anassociated conductive member to effect suitable connection with thescreen.

Basically, color cathode ray tubes of the postdeflection type commonlyemploy at least one electrode member which is oriented between theelectron gun assembly and the spacedly related patterned display screen.In its simplest form, this type of cathode ray tube is constructed tohave a color-selection or fo cusing electrode that is positioned inspaced adjaeency with the screen. The cathode ray tube of this type ofconstruction permits the use of larger openings or apertures in thecolor-selection electrode than those normally used in the conventionalshadow mask type of color tube. As a result, a screen display ofincreased brightness is possible in the post-deflection type of tube.Unfortunately, this achievement of improved brightness is not withoutattendant problems. In the post-deflection tube, the color-selection orfocusing electrode is normally operated at an electrical potential whichis of a value lower than that of the screen potential, this differencein related potentials is the primary determining factor as to whetherthe operation of the tube is post-deflection focusing or post-deflectionacceleration.

In a post-deflection tube, the lower potential for the color-selectionelectrode is usually applied thereto by a resilient connector attachedto the electrode in a manner to make contact with the conductive coatinginteriorly disposed on the inner surface of the funnel portion. Thiscoating conventionally receives its electrical potential from anexternal source via a metallic conductive button traversing the wallofthe funnel portion. Separate electrical conductive means are utilizedto supply a higher electrical potential to the screen portion of thetube.

At least three means have been used in the art to convey the higherpotential to the screen. One such means involves the utilization of aconductive button disposed in the sidewall of the panel portion in amanner to make contact with the periphery of the screen. Since themagnitude of the screen potential may be in the order of 30 KV orhigher, the proximity of the high voltage connection to the front of thetube may constitute a hazardous condition for the user. Another meansfor effecting an electrical transversal of the tube envelope has been anelectrical conductor disposed through the panel-funnel seal. A commonconnector thus employed has been a rather light'weight metallic stripembedded in the sealing frit in a manner to traverse the seal. Usuallythis has been a fragile type of connection requiring externalapplication of an insulative potting material thereabout to strengthenand shield the external portion of the connection. The fragility of suchconnections in the art have been a drawback to their commercial usage. Athird type of electrical transversal is in the form of a separateconductive button disposed in the sidewall of the funnel portionadjacent to the seal edge thereof. With this type of connection, theprior art discloses the use of a configuration of integrated connectivemembers supported and attached to the colorselection electrode in amanner that the connective members bridge the region of funnel-panelseal extending from a pad of conductive material disposed over theinterior surface of the conductive button to the edge of the displayscreen disposed within the panel portion. This integral bridgingconnective member is of complicated shaping and construction and as aresult, occu pies a considerable amount of critical space between theframe of the color-selection electrode and the sidewall of the panelportion. The nearness of the two ele' ments of different potentialsaggravates the possibility of arcing therebetween.

OBJECTS AND SUMMARY OF THE INVENTION It is an object of this inventionto reduce and obviate the aforementioned disadvantages that have beenevidenced in the prior art. Another object of the invention is toprovide a safe and convenient means for effecting a bridging electricalconnection between a discrete funnel-related area of a cathode ray tubeenvelope and an associated area disposed on the adjacent panel portionthereof. An additional object of the invention is to provide an improvedelectrical connection of the aforedescribed type that lends itself toexpeditious fabrication and utilization.

These and other objects and advantages are achieved in one aspect of theinvention wherein an improved electrical connective means is providedfor usage in a cathode ray tube to make bridging connection between aconductive area disposed in the funnel portion with an associatedconductive area disposed on the adjacent panel portion. A spanningconnection of this kind is expeditiously employed, for example, in apost-deflection type of cathode ray tube wherein the connective means ofthe invention is comprised of a metallic conductive button traversingthe wall of the funnel portion of the envelope and having a definedbonding region located on the inner surface whereupon a longitudinalresilient connective member is attached. This longitudinal metallicconnective member has a jointure region formed at one end thereof and acontact area at the other with a bridging resilient intermediate sectiontherebetween. The jointure region thereof is shaped to meet with and beaffixed to the bonding region of the button in a manner to direct theconnective member toward the screen. The contact area of the member iscontoured to effect slidable pressured contact with a peripheralconnective portion of the panel-disposed screen.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of anexemplary color cathode ray tube wherein the invention is illustrated;

FIG. 2 is an enlarged perspective view showing a portion of the tubeincorporating the improved electrical connective means of the invention;

FIG. 3 is an enlarged cross-sectional view showing the components of theinvention; and

FIG. 4 is a perspective illustrating one embodiment of the componentialbutton member of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT For a better understanding ofthe present invention, together with other and further objects,advantages and capabilities thereof, reference is made to the followingspecification and appended claims in connection with the aforedescribeddrawings.

While the bridging electrical connective means of the invention isgenerally applicable for effecting a connection between a funneldisposed electrical transversal and a related conductive area on theadjacent panel portion of a CRT envelope, for purposes of example, theinvention is described and shown herein as relating to a tube ofpost-deflection classification.

With particular reference to FIGS. 1 and 2, a color cathode ray tube 11of the post-deflection type of construction is shown as having alongitudinal axis 13 therethrough and an envelope 15 comprised of anintegration of neck, funnel, and face panel portions, l7, l9 and 21respectively, whereof the panel portion is hermetically joined to thefunnel portion along-the congruent seal 23 which is effected by afritting procedure during tube fabrication. The face panel 21 has aviewing area 25 and a substantially perimetrical sidewall portion 27which is terminated by the sealing seat 29 to which the funnel portion19 is attached. Formed on the interior surface of the viewing panel is apatterned cathodoluminescent screen 31 comprised of discrete areas ofcolor-emitting phosphor materials which are definitively disposed asstripes or dots in keeping with the state of the art. A discretelyapertured structure, in this instance referenced as a color-selectionelectrode 33, having an apertured area 34 and a supporting frame 25, isspatially related to the patterned screen 31. This electrode ispredeterminately positioned within the face panel by usual means in theart such as supporting stud-like members embedded in the side-wall ofthe panel in a manner to project therefrom and mate with locatorsintegral with the electrode member. For purposes of clarity, theseconventional stud-like supporting members and associated mask locatorshave been eliminated from the drawings. Attached to the framing portion35 of the color-selection electrode is a peripheral strip-like beamshielding means 37 which is positioned to extend from the frame of theelectrode, in a bridging manner, to make contact with the panel sidewall27 thereby protecting the patterned cathodoluminescent screen 31 fromdeleterious electron excitation resultant from the peripheral overscanof the several electron beams 39 emanating from the electron gunassembly 41 positioned in the neck portion 17 of the tube envelope. Asillustrated, the interior of the funnel portion 19 has a skirt-likeconductive coating 43 disposed thereon in a manner extendingsubstantially from the neck portion to the forward region adjacent thesealing zone 23. This envelopic coating, which is usually of thepotential of the final electrode of the electron gun assembly 41, isformed of a material, such as Aquadag, such being electrically connectedto the color-selection electrode, by means not shown. The electricalpotential is normally supplied to this skirt like coating by a relatedconductive metallic button 45 which is disposed to traverse the wall ofthe funnel portion 19.

The embodiment of the invention, as illustrated in FIGS. 1, 2, and 3, isan integrated conductive formation 47 comprising an envelope traversingelectrical conductor 49 in the form of a metallic conductive buttonwhich is disposed in the wall of the envelope funnel l5 portion in theregion thereof adjacent to the panelfunnel seal 23; conjunctivetherewith is a substantially longitudinal resilient metallic connectivemember 51 that is affixed or bonded to the interior surface of thefunnel-disposed button 49, and extended therefrom to make contact with aperipheral portion of the screen. As shown, a conductive tab 53 isformed as an extended area of the screen 31, such being disposed on thepanel sidewall 27 in a manner to extend toward the seal edge 29 of thepanel to expedite electrical contact with the connective member 51 ofthe connection combination 47.

The conductive button 49, which is sealed in the wall of the funnelportion 19 to traverse therethrough, is of substantially frusto-conicalshaping having a circumscribing sidewall 55 and substantially parallelspacedly related inner 57 and outer 59 portions, the integration thereofproducing a substantially hollow conductive element 49 with an opening60 formed in the outer surface. Electrical connection is made therewithby inserting the expandable terminal of an external source through theopening. The inner portion 57 of the button, which is oriented to theinterior of the funnel, is fabricated to have a solid stud-like jointureprotuberance 61 oriented in substantially the center region of the innersurface.

The metallic material from which the conductive button 49 is fabricatedhas a coefficient of thermal expansion which substantially matches thatof the glass of the funnel portion 19. An exemplary material is anickeliron alloy referenced as No. 4 alloy, which is commerciallyavailable from GTE Sylvania Incorporated, Warren, Pennsylvania.

Associated with the discretely shaped conductive button 49, is asubstantially longitudinal resilient metallic connective member 51formed of a suitable material, such as stainless steel, and having ajointure region 63 formed at one end thereof, a contact area 65 at theother, with a bridging resilient intermediate section 67 therebetween.The jointure region is formed as a substantially U-shaped configurationwhich is invertedly positioned on and affixed to the stud-likeprotuberance of the conductive button. With particular reference to FIG.3, the jointure region 63 of the connective member is mated with andbonded to the conductive button 49 prior to the joining of the panel andfunnel portions. The affixation of the U-shaped jointure configurationof the connective member to the projecting stud 61 of the button isexpeditiously accomplished by welding across the U-shaping through thesolid protuberance sandwiched therebetween. A forward contact area 65 isformed to have a substantially reverse-turned leading edge 69, whereofit is preferred to have the turnedunder terminal end located to effectslidable pressured contact with the connective portion 53 of the screen31. The reverse-turn of the contact area 65 provides a substantiallyrounded leading edge which facilitates sliding contact when the panelportion 21 is positioned and frit-seated on the funnel portion 19.Orienting the reverse-turn portion of the contact area 65 toward thepanel sidewall 27, eliminates a projection extending toward the colorselection electrode 33 and thereby reduces the possibility of anarc-inducing condition between the connective member and the electrode.It is to be noted in FIGS. 1 and 2 that the assembled connective meansprovides for close positioning to the sidewall of the envelope. This isparticularly advantageous since the spacing between the color-selectionelectrode 33 and the panel sidewall 27 is of narrow dimensioning.

Another embodiment of the conductive button 49' is illustrated in FIG.4, wherein the jointure protuberance 61' is formed as a substantiallyflattish stub-like tongue projecting from the inner surface 57 of thebutton.

When such is utilized, orientation of the plane of the,

stub 71 is substantially parallel with the seal line 23 joining thefunnel and panel portions. By such orienta tion of the tongue, theforward directional placement of the metallic connective member 51 isaccurately predetermined.

Thus, there is provided an improved internal connective means for usewith a cathode ray tube wherein a separate electrical connection iseffected from a defined wall-oriented electrical traversal to a discretearea of the panel. The connective means of the invention provides asimple but efficient connective combination that is both expedient andappropriate for cathode ray tube utilization. 7

While there has been shown and described what are at present consideredthe preferred embodiments of the invention it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the scope of the invention as defined bythe appended claims.

What is claimed is:

1. An electrical connective improvement in a cathode ray tubeincorporating an envelope formed of an integration ofa neck portionhaving an electron gun assembly located therein, a funnel portion joinedthereto,

said funnel portion being sequentially sealed to a contiguous panelportion having a cathodoluminescent screen formed on the inner surfacethereof with an electrode member oriented in spatial relationshipthereto, said improvement being the means for effect ing a bridgingelectrical connection from said funnel portion to said panel portioncomprising:

an isolated metallic conductive button traversing the wall of saidenvelope, said conductive button having a substantially defined bondingregion located on the inner surface thereof oriented within said tube;and a substantially longitudinal resilient metallic connective memberhaving a jointure region formed at one end thereof and a contact area atthe other with a bridging resilient intermediate section therebetween,said jointure region being mated with and affixed to the bonding regionof said button in a manner to direct said connective member toward saidpanel, said contact area of said connective member being contoured toeffect slidable pressured contact on a related area in said panel. 2.The connective improvement according to claim 1 wherein said bondingregion of said conductive button is formed as a solid stud-like jointureprotuberance oriented in substantially the center region of the innersurface of said button.

3. The connective improvement according to claim 2 wherein saidstud-like jointure protuberance is formed as a substantially flattishstub-like tongue, the orientation of the plane of said stub beingsubstantially parallel with the seal line joining said funnel and saidpanel portions.

4. The connective improvement according to claim 1 wherein the jointureregion of said connective member is formed as a substantially U-shapedconfiguration invertedly positioned on and affixed to said stud-likeprotuberance on said button.

5. The connective improvement according to claim 1 wherein the forwardcontact area of said connective member is formed to have a substantiallyreverseturned leading edge to facilitate sliding contact with a relatedpanel-disposed conductive area.

6. The connective improvement according to claim 1 wherein saidconductive button traverses the funnel portion of said envelope in theregion substantially proximal to the region of the panel-seal.

1. An electrical connective improvement in a cathode ray tubeincorporating an envelope formed of an integration of a neck portionhaving an electron gun assembly located therein, a funnel portion joinedthereto, said funnel portion being sequentially sealed to a contiguouspanel portion having a cathodoluminescent screen formed on the innersurface thereof with an electrode member oriented in spatialrelationship thereto, said improvement being the means for effecting abridging electrical connection from said funnel portion to said panelportion comprising: an isolated metallic conductive button traversingthe wall of said envelope, said conductive button having a substantiallydefined bonding region located on the inner surface thereof orientedwithin said tube; and a substantially longitudinal resilient metallicconnective member having a jointure region formed at one end thereof anda contact area at the other with a bridging resilient intermediatesection therebetween, said jointure region being mated with and affixedto the bonding region of said button in a manner to direct saidconnective member toward said panel, said contact area of saidconnective member being contoured to effect slidable pressured contacton a related area in said panel.
 2. The connective improvement accordingto claim 1 wherein said bonding region of said conductive button isformed as a solid stud-like jointure protuberance oriented insubstantially the center region of the inner surface of said button. 3.The connective improvement according to claim 2 wherein said stud-likejointure protuberance is formed as a substantially flattish stub-liketongue, the orientation of the plane of said stub being substantiallyparallel with the seal line joining said funnel and said panel portions.4. The connective improvement according to claim 1 wherein the jointureregion of said connective member is formed as a substantially U-shapedconfiguration invertedly positioned on and affixed to said stud-likeprotuberance on said button.
 5. The connective improvement according toclaim 1 wherein the forward contact area of said connective member isformed to have a substantially reverse-turned leading edge to facilitatesliding contact with a related panel-disposed conductive area.
 6. Theconnective improvement according to claim 1 wherein said conductivebutton traverses the funnel portion of said envelope in the regionsubstantially proximal to the region of the panel-seal.